Electromagnetic apparatus



April 22, 1941.

D. M. BERGES ELEGTROMAGNETIC APPARATUS Filed SepL 24, 1938 INVENTOR.

M. Be/'yes B Dona/d miJ d'1' Patented'Apr. 22, 1941 UNITED *s'ni'rlezsv .PATENT oFFlcF.

2,239,31z nLnc'raoMAGNE'rrc APPARATUS Donald M. Berges, Montclair, N. J., assigner to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application September 24, 1938, Serial No. 231,587 3 Claims. (Cl. 175-341) The invention relates to electromagnetic apparptus, and more particularly to the mechanical v construction thereof.

- An object of the invention is to improve the objectionable reciprocatory vmovement -oi.' the,

solenoid plunger. An object of the present in-l vention is to provide means for counter-acting this tendency and for controlling the effect thereof upon the solenoid plunger..

Other features of the invention residefinlthe actual construction, inter-relationship, and

method ofr assembly and operation of the partsr as more fully disclosed in the following descripv tion and 4accomplishing drawing. It -is to be understood, however, -that the drawing is for the purpose of illustration onlyl and is not designed as a denition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawing,

Fig. 1 is a longitudinal sectional view of a device embodying the invention; and

Fig. i!4 is an exploded perspective view of the plunger, fixed core, and spring.

Reference numeral I 0 indicates a cup-shaped shell or housing element closed at one end by 'Ihe member 25 extends inwardly from the plate I I and constitutes a xed magnetic pole piece centrally located within thesolenoid. A con`v necting member in the form of a rod 21 of nonmagnetic material is mounted to slide freely within pole piece 25, and is provided at one end with a stop 28 held thereon by suitable means 29 secured to the rod 21. At its opposite end connecting rod 21 carries movable core or plunger 30 of magnetic material and of slightly smaller diameter than the outside diameter of the iixed polef piece 25. The plunger is suitably lsecured to the connecting rod 21 as by means of a pin 43 and at its opposite end is centrally bored and threaded to receive a screw 33 and a stranded wire or cable 32 anchored iii said screw 33 as indicated at 3|, said cable having connection at its opposite end (not shown) with the device to be actuated such as, for example, the clutch shifting mechanism of the above identified Lansing patent. Also as in said Lansing patent a -suitable spring or equivalent means (not shown) will be provided to maintain the plunger 30 in the position indicated in Fig. 1 until such time asV current is caused to ow through the solenoid winding 34, whereupon the resulting magnetic iield produces an inward movement of the plunger 30 to close the gap between the cooperating pole pieces 30 and 25 and thus producing movement of the linkage of which the elements 32 and 33 are suitable parts. The spool 38 of suitable insulating material surrounds the non-magnetic plunger guidesleeve 42 and receives the solenoid winding 34 as well as the terminal postsv35 and r36 which, as shown, are molded in the head portion 31 f of the spool 33. At their outer ends the terminal a plate Il extending transversely thereof and provided with means in the form of a flange l2 by which the device may be mounted upon a suitable support or upon the housing of another device with which it may be operatively'associated, as for exampleran'engine starting mechanism of the character shown in Patent No. 1,833,948 granted to Raymond `P. Lansing on December 4, 1931, whichmechanism includes an engine-engaging clutch element -shiftable in vone direction in response to energization of a solenoid whose movable core or. plunger is mechanically interlinked with' said engine engaging clutch element by any suitable means.

The plate Il isprovided with a central opent ing, and a guide member 25 is mounted with its upper end suitably :dxed in said opening as by means of the upset flange or lip indicated at 26.

posts 35 and 36 receive conductor attaching means in the form of nuts 4l and 45 and terminal elements 45, said conducting parts being insulated from the housing element Il by suitable non-conducting bushings as indicated at 33 and 45. Conductors for attachment to terminals 45 may be led'lnto the housing 41 through opening 44.

As indicated best in Fig. 2 the novel means of the present invention for preventing undesired transverse or other movement of the plunger 3l during nperiods of nonenergization of the solenoid, includes a at resilient element in the nature of a spring of the leaf type having one end thereof turned as indicated .at 5|. for reception in a correspondingly shaped transverse slot 52 provided in the x`ed core element 25 at the portion thereof which registers with the lonplunger against any movement except that which is induced by the superior force resulting from actual energization of the solenoid wire 34. Since such energization occurs only occasionally the amount of wear upon the plunger and associated parts is held/to a minimum, all the excessive wear due to unchecked impulses which are normally transmitted to such a device because of its association with some other constantly operating mechanism such as an internal combustion engine, being eliminated by the absorbing and damping action of the spring 55.

It will be understood that the two ends (not shown) of the winding 34 connect with the terminal posts 35 and 36, to which they are mechanically and electrically held in any conventional manner, the head portion 3l -of the spool 38 being suitably recessed adjacent said terminal posts to receive said wire ends. y

What is claimed is:

l. 'I'he combination with a solenoid spool and a magnetic pole-piece secured thereto, of a second pole-piece slidable along the axis of the rst-named pole-piece and spool, said second pcie-piece having a at exterior surface extending longitudinally thereof, and means comprising a fiat-sided resilient strip engageable with said at exterior surface, and interposed between sad spool and slidable pole-piece and operable in any attitude from the horizontal ,to the vertical to yieldably hold the latter against transverse and turning movements during periods of solenoid deenergization.

2. The combination with a magnetic polepiece, of a second pole-piece slidable along the axis of the rst-narned pole-piece, said second pole-piece having a iiat exterior surface extending longitudinally thereof, and means mounted in said first-named pole-piece in any attitude from the horizontal to the vertical and acting upon the slidable pole-piece to yieldably hold the latter against transverse and turning movements, said means comprising a nat-sided resilient strip engageable with said iiat exterior surface on said slidable pole-piece, in every position of the latter, to restrain al1 movement thereof, except axial movement.

3. The combination with a solenoid spool and a magnetic pole-piece secured thereto, of a second pole-piece slidable along the axis of the rst-named pole-piece and spool, said second pole-piece having a iiat exterior surface extending longitudinally thereof, and means mounted in said first-named pole-piece and acting upon the slidable pole-piece and operable in any attitude from the horizontal to the vertical to yieldably hold the latter against transverse and turning movements during periods of solenoid deenergization, said holding means being disposed wholly within the bore of said spool, and having only surface contact therewith.

DONALD M. BERoEs. 

